Tasmania Police do not keep data about the duration of the incidents attended to by the Special Operations Group, according to a Right to Information request.
The absence of record keeping, which was revealed to The Examiner through an RTI, has been defended by Tasmania Police deputy Commissioner Scott Tilyard.
He said data related to time allocation for the tactical response team's deployments was not held in one place because it involved planning, travel and investigation.
An SOG member for 12 years, Tasmanian Police Association assistant-secretary Andrew Bennett said during his time with the elite tactical response team they kept internal records of incident duration for a number of reasons.
"It's not just fatigue and OH&S, it's more so the total time away from either their primary roles or interrupting their time off," he said.
Deputy Commissioner Tilyard said incident duration data was "not a meaningful measure".
In recent the years, the union has pushed for the SOG to be reestablished as a full-time squad.
"These are important metrics that would inform the need for a full-time tactical unit," Mr Bennett said.
"This is Tasmania Police's biggest arsenal, this is their biggest group to resolve high-risk incident and you can't even say how long each deployment takes - it is 2019.
The RTI also revealed the tactical response team attended 26 high-risk deployments and 57 capability deployments in the past five years, including the 2018-19 financial year to February 28.
Capability deployments are necessary when the level of risk is outside a realm of normal police and high-risk deployments are situations where an act of unlawful violence has been or is likely to be committed, and that act may expose people or property to danger.
"The high-risk call outs tend to require the entire footprint of the SOG, whereas capability jobs might not," Mr Bennett said.
"The higher risk jobs they tend to get resolved quicker, although in 2004 we had the New Norfolk siege that lasted three days versus my last job that involved five days of special covert observations.
"What people forget in the world of tactical policing is they can't get it wrong because, if they do, there is no one left to pick up the pieces. That is the most critical thing - there is no one left behind you," Mr Bennett said.
Seven SOG members are on call at all times, with many of those attending incidents in their specialist role after working eight to 10-hour shifts in their primary police positions.
The tactical response members are also required to attend 45-days training each year.
In the 2018-19 budget, the state government pledged an additional $240,000 over two years from 2020-2021 to support a full-time SOG.
The union has previously raised concerns about the impact of having a part-time tactical response team, including being absent from their primary role because of multi-day deployments with the SOG.
A commissioner needs to sign-off on the deployment of the SOG.
"If the deployment criteria was reviewed and made more contemporary with other jurisdictions, and taking away a commissioner-level approval for deployment, their use would go up," Mr Bennett said.
"It is always reported that people don't use the SOG because it is too complicated and too hard."
Mr Bennett said reviewing the call-out procedures and giving the SOG responsibility in the three districts to patrol and respond to incidents with their less lethal capabilities would assist police to resolve incidents.
Tasmania is the only jurisdiction in the nation without a full-time tactical response team.